PROJECT SUMMARY Survivors of childhood and young adult cancer have a substantial risk of developing a second cancer, including Human Papillomavirus (HPV)-related cancers. Female childhood cancer survivors have 40% relative excess and male survivors have 150% relative excess of HPV-associated malignancies compared to the general population. Since 2009, the Children?s Oncology Group guidelines have recommended HPV vaccination to reduce the risk for HPV-related cancers for all eligible childhood cancer survivors. The limited research to date demonstrates low uptake and completion of the 3-dose HPV vaccination series among survivors of childhood cancer. However, these studies have been focused on self-report assessments at single institutions among female survivors. Evaluating HPV vaccination among survivors in Utah is of great public health importance as Utah?s 3-dose HPV vaccine series completion is among the lowest in the nation for both female teens (49th state) and male teens (43rd state). As many survivors of childhood cancer do not expeditiously transition back to primary care at the end of their cancer treatment, it is likely that their rates of HPV vaccination completion are even lower than the general population. We propose the first statewide assessment of HPV vaccination among both female and male childhood cancer survivors and an age and sex-matched general population comparison group from a largely rural state with low rates of HPV vaccination over a nine year time period (2006-2015). Building on two statewide resources 1) the Utah Population Database, which is linked to clinical data from Intermountain Healthcare, including Primary Children?s Hospital, where the majority of pediatric cancers in Utah are treated, and the 2) Utah Statewide Immunization Information System, we will conduct the first statewide evaluation of the rate of HPV vaccination among a sample of 1,863 childhood cancer survivors. Using UPDB allows us to generate an age and sex-matched general population comparison group without cancer to compare to the survivors. Our outcomes of interest are HPV vaccination initiation, receipt of 2 doses, 3-dose completion, and missed opportunities (defined as a healthcare visit when a patient received at least one immunization, but not a HPV vaccine dose). In the first aim, we will compare HPV vaccination among survivors of childhood cancer with the general population. In the second aim, we will identify high-risk groups of survivors of childhood cancer, such as survivors who are Hispanic, publically-insured, rural, and living in a health professional shortage area, who may be more likely to forego the HPV vaccine. At the end of the study, we will have identified whether both male and female childhood cancer survivors are less likely to get the HPV vaccine compared to adolescents and young adults without cancer. Also, we will establish at statewide level whether certain childhood cancer survivors (e.g., Hispanic) are more likely to miss getting the HPV vaccine, which is essential information to developing cancer prevention strategies for this growing population.